Basisdocument radon

Abstract

The document contains a critical risk-evaluation of Radon to humans and the environment. Radon is an inert gas of which the main risk is induction of lung cancer. Considering the nature of its effects and its presence only the by-products of Rn-222 are important for man in the indoor environment. In the indoor environment the average Rn-222 concentration is about 10 times higher than in the outdoor air. The average exposure to Radon in the Netherlands results in an estimated risk of 60 cases of fatal lung cancer per million people per year, of which 80% as a result of Rn-222 and 20% as a result of Rn-200. This risk is partly present by nature (the emission is determined by the soil for about 95%) and is therefore not always controlable. Without taking measures the risk will increase as a result of building new houses. By taking measures in all houses that will be built in future (increased ventilation of crawl space, sealing the ground floor) an annual decrease of the average individual risk of o.6% seems attainable. The spread of the exposure level is large and restriction of the individual risks can only be reached by organizing the problems.